The National Weather Service in Las Vegas issued an extreme heat warning Monday afternoon that covers parts of San Bernardino County from 10 a.m. Tuesday through 8 p.m. Friday. The alert calls for prolonged, dangerously hot conditions across the Mojave Desert and adjacent valleys that could pose serious health risks and disrupt daily activities.
What to expect
Forecasters say the most intense heat will affect the desert and lower-elevation river valleys. Temperatures are expected to reach 115 to 118 degrees in Death Valley and the lower Colorado River Valley, while other inland areas are forecast to see daytime highs in the 107 to 110 degrees range.
| Area | Forecast high |
|---|---|
| Death Valley / Lower Colorado River Valley | 115–118°F |
| Other inland areas (including parts of San Bernardino County) | 107–110°F |
Health and safety guidance
The NWS highlighted the increased risk of heat-related illness during an extended hot spell and urged residents to take precautions. Key safety steps include:
- Drink plenty of fluids and avoid alcohol or caffeine when possible.
- Stay in air-conditioned spaces; seek cooling centers if your home lacks AC.
- Limit outdoor exertion, especially during the hottest part of the day; reschedule strenuous work for early morning or evening.
- Never leave children or pets in a parked car, even for a short time.
- Check on elderly or medically vulnerable neighbors and relatives.
"Dangerously hot conditions with temperatures up to 115 degrees to 118 degrees expected through Death Valley and the lower Colorado River Valley, with highs between 107 to 110 degrees elsewhere."
Employers and workers who spend time outside should follow the Occupational Safety and Health Administration guidance to incorporate frequent rest breaks and access to shade or air-conditioning. The NWS also advised people to know the signs of heat exhaustion and heat stroke and to seek immediate help if symptoms develop.
Local impacts and preparedness
San Bernardino County stretches from densely populated urban neighborhoods to remote desert landscapes; residents in low-elevation desert communities are most vulnerable to the extremes forecast this week. High overnight lows that fail to provide relief can increase cumulative heat stress, particularly for those without reliable cooling at home.
Local public-health and emergency management officials typically coordinate to open cooling centers and share information about resources. Residents should monitor official county and city channels for the locations and hours of any cooling facilities, as well as updates about utility conservation notices or transportation advisories that can accompany prolonged heat waves.
Heat also raises the risk of wildfire starts and can complicate firefighting operations. With hot, dry conditions in place across the region, those who live and work in wildland-urban interface areas should review evacuation plans and keep emergency kits accessible.
When to call for help
If someone shows signs of heat stroke — including high body temperature, altered mental state, or loss of consciousness — move the person to a cool or shaded area, cool them with water, and call 911 immediately. For less severe heat-related symptoms, such as heavy sweating, weakness, or dizziness, seek shade, hydrate, and contact a health provider if symptoms persist.
Residents are encouraged to stay informed through the National Weather Service, San Bernardino County Public Health, and local municipal alerts for the duration of the warning. The NWS said the warning remains in effect until 8 p.m. Friday.
